Composition consisting of brewer's spent grains and polylactic acid and a method for making the same

Abstract

A method for manufacturing a composition consisting of brewer's spent grains and polylactic acid includes the steps of: providing a raw material containing brewer's spent grains; providing a raw material containing polylactic acid; mixing the brewer's spent grains with the polylactic acid at a specific proportion; and providing a binder to enable the brewer's spent grains and the polylactic acid to be well mixed, and to maintain a desired tensile strength. A pretreatment unit includes a dehydration process, a desiccation process, a drying process, a grinding process and a sieving process. A granulator includes a double screw extruder connected with a cutting machine. The double screw extruder mixes the PLA material and the brewer's spent grains and extrudes them into plastic bars which are then cut into plastic granules by the cutting machine.

What is claimed is: 
     
       1. A method for manufacturing a composition consisting of brewer's spent grains and polylactic acid, comprising the following steps:
 a step a of providing a raw material containing brewer's spent grains; 
 a step b of providing a raw material containing polylactic acid; and 
 a step c of mixing the brewer's spent grains of a proportion of 10% to 30% by weight with the polylactic acid of a proportion of 70% to 90% by weight; 
 wherein the step a includes a pretreatment unit which uses a dehydration process, a desiccation process, a drying process, a grinding process and a sieving process to process the brewer's spent grains into brewer's spent grains which have a length-to-diameter ratio of 7.6 to 10.2, and a moisture content of the brewer's spent grains is controlled at 2%. 
 
     
     
       2. The method as claimed in  claim 1  further comprising a step d of providing a binder, and the binder is at a proportion of 3% to 12% by weight. 
     
     
       3. The method as claimed in  claim 2 , wherein the brewer's spent grains is at a proportion of 10% by weight, and the binder is at a proportion of 8% by weight. 
     
     
       4. The method as claimed in  claim 2 , wherein the step a includes a granulator which includes a double screw extruder connected with a cutting machine, the cutting machine includes a polylactic acid feeding port, a brewer's spent grains feeding port and a discharge port, the cutting machine includes an input hole and an output hole, the discharge port communicates with the in put hole, the double screw extruder mix the polylactic acid material and the brewer's spent grains and press them into plastic bars, and the bar-shaped plastic bars are cut into plastic granules by the cutting machine.